Threats to Jhin with this build
|Ezreal||Ezreal will be doing the same thing as you, just trying to farm and avoid fighting. This is good for you as you outscale him very hard and his poke can be negated by some lifesteal/good dodging. Make sure to remember he can easily get out of his Curtain Call by arcane shifting over terrain, and he can line up his own ulti whilst you channel. Other than that, just outscale with ease. Stay behind/inside your creep wave so he cant Q poke you.|
|Kog'Maw||Late game god, but requires his team to keep him safe. Early-mid game, he's incredibly weak and can easily be pushed around. Early game always force fights and grenade bounces. Thanks to his low mobility, you can easily set up your E, W combo and show him his Curtain Call.|
|Nami||Another buff/pick support (common trend). Nami is great with champions who can auto attack 3 times pretty much every trade (Ezreal, Caitlyn, Lucian for example) as they can make the most use out of her E. She can heal/poke people with her W which is nice, and her Q is a pretty slow AoE stun knockup thing. Abuse the fact she hates all ins and after 3 auto attacks and her W, she's useless. Dodge her Q and let your support eat then W. Her ult is greta disengage and pseudo engage, slow moving and huge. Super simple lane, but can easily be swung in your enemies favour if you take bad fights with her E.|
|Taliyah||Being a fairly new champion not many people have mastered Taliyah, however even a great one isn't a huge threat for Jhin (if the Taliyah is a support, which this guide assumes so). Dodge her Q by standing behind creeps or simply walking away when she channels it, if she's on her circle of worked group then it's like an auto attack. Try to run out of her W by moving erratically or simple staying away from her E, which is the mine field. You don't have to worry about her E's interaction with Dashes as you have none. Her ultimate is AMAZING at catching targets and creating fights. If you're going to be pinned against it double check to see if you can win the fight or not. If you can't, flash over as soon as Taliyah appears (because she might be stupid and fly at you with 1hp) or simply accept your fate and wait to respawn. All in all, she's a great pick like support that is potent against dashes. Jhin is strong against pick due to his range and has no dashes. Any questions?|
Greater Mark of Attack Damage - As a Jedi, having more Attack Damage is always better. Extra damage on Alpha Strike as well as more potent auto attacks.
Greater Mark of Critical Chance - While not a necessity, having the ability to critically strike (however low chance it is) before buying any crit items can come in great use every so often.
Greater Seal of Armor - Seals are the most flexible of runes for Yi - choose whatever suits you best. I like to take armour runes just for general durability against auto attacks, jungler ganks and even minion hits.
Greater Glyph of Magic Resist - Having magic resistance seals is important to help negate against AP damage, however it is optional as to whether you choose FLAT runes or SCALING runes. I use scaling runes to transition Yi's early to mid game strength into the late game by adding some durability.
Greater Quintessence of Attack Speed - Attack speed runes are fairly standard on AD type champions nowadays, and Yi is no different. He is very strong with attack speed which allows him to proc his passive more frequently, apply more on-hit true damage, and generally do higher DPS. The reason I choose these over flat AD quints is that with a Doran's Blade start and Brutalizer rush, you have a fairly decent amount of AD already but don't usually get any attack speed until boots.
Pros / Cons
+Strong farmer with auto attacks, Double Strike and Alpha Strike
+Decent lane sustain and burst tankiness through Meditate
+Doesn't require blue buff if played carefully
+Highest base movement speed (tied with Pantheon)
+Easy escapes, ganks & pushes thanks to Highlander
+Strong AD scaling AND good base damage
-No crowd control whatsoever
-Can get bullied in lane - melee in ranged-dominated environment
-Relatively low base health pool and resistances
-Susceptible to ganks when abilities are on cooldown
-Still not widely accepted as viable mid (people will call you "troll")
-Requires Chosen skin for true Jedi ascension
Tier 1: Given the two choices in the first tier it is fairly obvious we should choose Fury . Additional attack speed is great on Yi as he is an auto-attack based champion. Sorcery is not effective on Yi as he only has one damaging spell.
Tier 2: Here both choices are viable and it is mainly up to you. Personally I believe that an additional 3% damage from Double Edged Sword is not going to make a considerable difference (and will also increase damage done to Yi) whereas healing 20 HP from a minion kill every so often can be useful in the laning phase to stay in lane.
Tier 3: I recommend Vampirism here as the extra life steal is very useful for sustain during combat and the AD we get from Natural Talent isn't really that significant compared to your item build and Wuju Style.
Tier 4: I would DEFINITELY choose Bounty Hunter here as Yi has zero CC in order to use Oppressor which means you would be relying on your teammates. As a solo mid this is obviously not a great idea so we should opt for the (potential) 5% damage increase from Bounty Hunter instead.
Tier 5: Battering Blows is the only real choice here. We do no magic damage so MPEN is useless. Extra armour penetration is always useful and unless you decide to purchase some penetration in your build this may be the only source of it.
Tier 6: Last but not least we have the keystone. We are going to have a significant amount of critical strike rating in this build so I would highly recommend picking up Warlord's Bloodlust . In it's current state (5.22) it is very strong and a highly useful mastery to bring. Alternatively we have Fervor of Battle which is also potentially very strong thanks to Yi's fast attack speed however I find the healing from Warlord's Bloodlust too good pass up. We also have Deathfire Touch to consider - while I personally wouldn't recommend it, it could have a large amount of damage due to resetting Alpha Strike and our high bonus AD (untested).
Tier 1: Wanderer is great on a midlaner as we should be ganking wherever possible, and Boots of Mobility really aren't viable on Yi. I would only recommend our other option, Savagery, if you are perhaps not level 30 and don't have the required runes to make last hitting easy. If you find yourself struggling to properly kill creeps then this mastery can be useful early game.
Tier 2: Either option is good here - with that being said I'd opt to run Secret Stash to make our potions a little bit more useful and return us some much needed mana. Not to mention having an extra 10% duration on Elixir of Wrath is not something to pass up. Alternatively we can choose to run extra buff duration which is great if you are expecting to receive blue buff often or have planned to take Rift Herald with your jungler.
Tier 3: Merciless is the recommended choice here as it improves Yi's ability to assassinate targets and get his much needed resets. The other option, Meditation , might seem tempting but overall it won't provide much mana regeneration as it is percentage based and we don't (usually) include mana items our build.
Tier 4: Dangerous Game is perfect for a cleanup assassin type champion such as Yi who is likely to get kills in rapid succession. It works perfectly with Highlander's resets and allows you to get off more spells during combat. The other option, Bandit , is mainly used for supports and is mostly useless for a mid laner as we are not going to be attacking the opponent frequently enough to make use of the extra gold.